Three-dimensional shaping device and method of shaping three-dimensional shaped article

ABSTRACT

A three-dimensional shaping device includes a supply flow channel through which a shaping material flows, an ejection amount control mechanism that controls a flow amount of the shaping material to be ejected from a nozzle, a branch flow channel branched from a first partial flow channel as a flow channel between the melting section and the ejection amount control mechanism out of the supply flow channel, a transfer mechanism that transfers the shaping material in the second partial flow channel to the first partial flow channel via the branch flow channel, and a control section that controls the transfer mechanism to transfer the shaping material in the second partial flow channel to the first partial flow channel in a period from stopping the ejection of the shaping material from the nozzle to resuming the ejection.

The present application is based on, and claims priority from JPApplication Serial Number 2019-062330, filed Mar. 28, 2019, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a three-dimensional shaping device anda method of shaping a three-dimensional shaped article.

2. Related Art

For example, in JP-A-2006-192710, there is described a device whichejects a melted thermoplastic shaping material on a platform from anozzle making a scanning movement in accordance with shape data set inadvance, and further stacks the melted shaping material on the shapingmaterial having cured on the platform to thereby form athree-dimensional shaped article.

In such a device for ejecting the shaping material from the nozzle asthe device described above, since the shaping material droops like afilament from the nozzle in some cases, or the shaping materialremaining in the nozzle denatures in some cases after stopping theejection of the shaping material from the nozzle, in order to improvethe quality of the three-dimensional shaped article, a further device isrequired.

SUMMARY

According to an aspect of the present disclosure, there is provided athree-dimensional shaping device. The three-dimensional shaping deviceincludes a melting section configured to melt a material to generate ashaping material, a supply flow channel which is communicated with themelting section, and through which the shaping material flows, a nozzlecommunicated with the supply flow channel and configured to eject theshaping material, an ejection amount control mechanism provided to thesupply flow channel, and configured to control a flow amount of theshaping material to be ejected from the nozzle, a branch flow channelbranched from a first partial flow channel as a flow channel between themelting section and the ejection amount control mechanism out of thesupply flow channel, and communicated with a second partial flow channelas a flow channel between the ejection amount control mechanism and thenozzle out of the supply flow channel, a transfer mechanism configuredto transfer the shaping material in the second partial flow channel tothe first partial flow channel via the branch flow channel, and acontrol section configured to control the ejection amount controlmechanism and the transfer mechanism. The control section controls thetransfer mechanism to transfer the shaping material in the secondpartial flow channel to the first partial flow channel in a periodobtained by summing a first period from controlling the ejection amountcontrol mechanism to stop ejection of the shaping material from thenozzle to controlling the ejection amount control mechanism to resumethe ejection of the shaping material from the nozzle, and a secondperiod after controlling the ejection amount control mechanism to resumethe ejection of the shaping material from the nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram showing a schematic configuration of athree-dimensional shaping device according to a first embodiment.

FIG. 2 is a schematic perspective view showing a configuration on agroove forming surface side of a flat screw.

FIG. 3 is a top view showing a configuration of an opposed surface of ascrew of a barrel.

FIG. 4 is an explanatory diagram showing a configuration of an ejectionamount control mechanism and a transfer mechanism.

FIG. 5 is a perspective view showing a configuration of a valve part.

FIG. 6 is a first explanatory diagram showing an operation of the valvepart.

FIG. 7 is a second explanatory diagram showing the operation of thevalve part.

FIG. 8 is an explanatory diagram showing a flow of a shaping materialwhen pulling a plunger.

FIG. 9 is an explanatory diagram showing a flow of the shaping materialwhen pushing the plunger.

FIG. 10 is a flowchart showing a content of a shaping process in thefirst embodiment.

FIG. 11 is a flowchart showing a content of a shaping process in asecond embodiment.

FIG. 12 is a flowchart showing a content of a shaping process in a thirdembodiment.

FIG. 13 is a flowchart showing a content of a transfer process in thethird embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS A. First Embodiment

FIG. 1 is an explanatory diagram showing a schematic configuration of athree-dimensional shaping device 100 according to a first embodiment. InFIG. 1 , there are shown the arrows along X, Y, and Z directionsperpendicular to each other, respectively. The X direction and the Ydirection are directions along a horizontal direction, and the Zdirection is a direction along a vertical direction. In other drawings,there are arbitrarily shown the arrows along the X, Y, and Z directions,respectively. The X, Y, and Z directions in FIG. 1 and the X, Y, and Zdirections in other drawings show the same directions, respectively.

The three-dimensional shaping device 100 according to the presentembodiment is provided with a shaping unit 200, a stage 300, a transfermechanism 400, and a control section 500. The three-dimensional shapingdevice 100 drives the transfer mechanism 400 to change the relativeposition between a nozzle 61 and a shaping surface 310 while ejectingthe shaping material from a nozzle 61 provided to the shaping unit 200toward the shaping surface 310 of the stage 300 under the control by thecontrol section 500 to thereby shape a three-dimensional shaped articlehaving a desired shape on the shaping surface 310.

The transfer mechanism 400 changes the relative position between thenozzle 61 and the shaping surface 310. In the present embodiment, thetransfer mechanism 400 moves the stage 300 with respect to the shapingunit 200 to thereby change the relative position between the nozzle 61and the shaping surface 310. The transfer mechanism 400 in the presentembodiment is formed of a triaxial positioner for moving the stage 300in triaxial directions, namely the X, Y, and Z directions with drivingforces of three motors. Each of the motors is driven under the controlby the control section 500. It should be noted that it is also possiblefor the transfer mechanism 400 to be provided with a configuration ofchanging the relative position between the nozzle 61 and the shapingsurface 310 by moving the shaping unit 200 without moving the stage 300instead of the configuration of moving the stage 300. Further, it isalso possible for the transfer mechanism 400 to be provided with aconfiguration of moving both of the stage 300 and the shaping unit 200to thereby change the relative position between the nozzle 61 and theshaping surface 310.

The control section 500 is formed of a computer provided with at leastone processor, a main storage device, and an input/output interface forperforming input/output of a signal with the outside. In the presentembodiment, the control section 500 controls the operations of theshaping unit 200 and the transfer mechanism 400 by the processorexecuting a program and a command retrieved on the main storage deviceto perform the shaping process for shaping the three-dimensional shapedarticle. In the operation, there is included a shift of athree-dimensional relative position between the shaping unit 200 and thestage 300. It should be noted that it is also possible for the controlsection 500 to be formed by a combination of a plurality of circuitsinstead of the computer.

The shaping unit 200 is provided with a material supply section 20 as asupply source of the material, a melting section 30 for melting thematerial supplied from the material supply section 20 to make theshaping material, and an ejection section 60 having the nozzle 61 forejecting the shaping material supplied from the melting section 30.

In the material supply section 20, there is housed a material in theform of a pellet, a powder, or the like. In the present embodiment, ABSresin formed to have a pellet shape is used as the material. Thematerial supply section 20 in the present embodiment is formed of ahopper. A supply channel 22 for coupling the material supply section 20and the melting section 30 to each other is disposed below the materialsupply section 20. The material supply section 20 supplies the meltingsection 30 with the material via the supply channel 22.

The melting section 30 is provided with a screw case 31, a drive motor32, a flat screw 40, and a barrel 50. The melting section 30 melts atleast a part of the material in a solid state supplied from the materialsupply section 20 to make the shaping material in paste form havingfluidity, and then supplies the shaping material to the ejection section60.

The screw case 31 is a housing for housing the flat screw 40. To thelower surface of the screw case 31, there is fixed the barrel 50, and ina space surrounded by the screw case 31 and the barrel 50, there ishoused the flat screw 40. To the upper surface of the screw case 31,there is fixed the drive motor 32. The rotary shaft of the drive motor32 is coupled to the upper surface 41 side of the flat screw 40. Thedrive motor 32 is driven under the control by the control section 500.

The flat screw 40 has a substantially cylindrical shape small in heightin a direction along a central axis RX than the diameter. The flat screw40 is disposed inside the screw case 31 so that the central axis RXbecomes parallel to the Z direction. Due to the torque generated by thedrive motor 32, the flat screw 40 rotates around the central axis RXinside the screw case 31.

The flat screw 40 has a groove forming surface 42 having groove parts 45formed on the opposite side to the upper surface 41 in a direction alongthe central axis RX. It should be noted that a specific configuration ofthe flat screw 40 and the groove parts 45 will be described later.

The barrel 50 is disposed below the flat screw 40. The barrel 50 has ascrew-opposed surface 52 opposed to the groove forming surface 42 of theflat screw 40. The barrel 50 is provided with a communication hole 56communicated with the ejection section 60 disposed on the central axisRX of the flat screw 40. The barrel 50 incorporates a heater 58 at aposition opposed to the groove parts 45 of the flat screw 40. Thetemperature of the heater 58 is controlled by the control section 500.It should be noted that the detailed configuration of the screw-opposedsurface 52 will be described later.

The ejection section 60 is fixed to a lower surface of the barrel 50.The ejection section 60 is provided with a supply flow channel 62 whichis communicated with the melting section 30, and through which theshaping material supplied from the melting section 30 flows, the nozzle61 which is communicated with the supply flow channel 62, and whichejects the shaping material, and an ejection amount control mechanism 70which is provided to the supply channel 62, and which controls the flowamount of the shaping material ejected from the nozzle 61. The supplyflow channel 62 has a first partial flow channel 63 as a part betweenthe melting section 30 and the ejection amount control mechanism 70, anda second partial flow channel 64 as a part between the ejection amountcontrol mechanism 70 and the nozzle 61. In the present embodiment, thefirst partial flow channel 63 is constituted by a first supply port 65and a through hole 66. The second partial flow channel 64 is formed of asecond supply port 67. The first supply port 65 extends in the verticaldirection. An upper end of the first supply port 65 is coupled to thecommunication hole 56 of the barrel 50, and a lower end of the firstsupply port 65 is coupled to the through hole 66. The second supply port67 extends in the vertical direction. An upper end of the second supplyport 67 is coupled to the through hole 66, and a lower end of the secondsupply port 67 is coupled to the nozzle 61. The shaping materialsupplied from the communication hole 56 of the barrel 50 to the firstsupply port 65 flows through the through hole 66, the second supply port67, and the nozzle 61 in this order.

The nozzle 61 is provided with a nozzle flow channel 68 and a nozzlehole 69. The nozzle flow channel 68 is a flow channel disposed insidethe nozzle 61. The nozzle flow channel 68 is coupled to the secondsupply port 67. The nozzle 69 is a part disposed at an end part on theside communicated with the air of the nozzle flow channel 68, and is apart reduced in flow channel cross-section. The shaping materialsupplied from the second supply port 67 to the nozzle flow channel 68 isejected from the nozzle hole 69. In the present embodiment, the openingshape of the nozzle hole 69 is a circular shape. It should be noted thatthe opening shape of the nozzle hole 69 is not limited to the circularshape, but can also be a quadrangular shape or the like.

The ejection amount control mechanism 70 is provided with a valve part73 disposed inside the through hole 66, and a first drive section 81 forrotating the valve part 73. The first drive section 81 is formed of anactuator such as a stepping motor, and rotates the valve part 73 insidethe through hole 66 under the control by the control section 500. Theejection amount control mechanism 70 rotates the valve part 73 tocontrol the flow amount of the shaping material flowing from the firstsupply port 65 to the second supply port 67 to thereby control the flowamount of the shaping material to be ejected from the nozzle 61. Theflow amount of the shaping material to be ejected from the nozzle 61 isalso referred to as an ejection amount. It should be noted that aspecific configuration of the ejection amount control mechanism 70 willbe described later.

On the outer circumference of the second supply channel 67, there isdisposed a nozzle heater 160. The nozzle heater 160 heats the shapingmaterial in the second supply port 67. The temperature of the nozzleheater 160 is controlled by the control section 500. It should be notedthat the nozzle heater 160 is also referred to as a heating section insome cases.

FIG. 2 is a schematic perspective view showing a configuration on thegroove forming surface 42 side of the flat screw 40. In FIG. 2 , theposition of the central axis RX of the flat screw 40 is represented bythe dashed-dotted line. As described with reference to FIG. 1 , thegroove forming surface 42 is provided with the groove parts 45.

A central part 47 of the groove forming surface 42 of the flat screw 40is formed as a recessed part to which one end of each of the grooveparts 45 is coupled. The central part 47 is opposed to the communicationhole 56 of the barrel 50 shown in FIG. 1 . The central part 47 crossesthe central axis RX.

The groove parts 45 of the flat screw 40 each form a so-called scrollinggroove. The groove parts 45 each extend in a vortical manner from thecentral part 47 toward the outer circumference of the flat screw 40 soas to draw an arc. The groove parts 45 can also be formed so as toextend in a spiral manner. The groove forming surface 42 is providedwith convex stripe parts 46 each constituting a sidewall part of each ofthe groove parts 45, and extending along the groove parts 45.

The groove parts 45 each continue to a material introduction port 44formed on a side surface 43 of the flat screw 40. The materialintroduction port 44 is a part for receiving the material supplied viathe supply channel 22 of the material supply section 20.

In FIG. 2 , there is shown an example of the flat screw 40 having threegroove parts 45 and three convex stripe parts 46. The number of thegroove parts 45 and the number of convex stripe parts 46 provided to theflat screw 40 are not limited to three. It is possible to provide justone groove part 45 to the flat screw 40, or to provide a plurality of,namely two or more, groove parts 45 to the flat screw 40. Further, it isalso possible to dispose an arbitrary number of convex stripe parts 46in accordance with the number of the groove parts 45.

In FIG. 2 , there is illustrated an example of the flat screw 40 havingthe material introduction ports 44 formed at three places. The number ofthe places where the material introduction ports 44 are disposed in theflat screw 40 is not limited to three. It is possible to dispose thematerial introduction port 44 at just one place in the flat screw 40, orto dispose the material introduction ports 44 at a plurality of places,namely two or more places, in the flat screw 40.

FIG. 3 is a top view showing a configuration of the screw-opposedsurface 52 of the barrel 50 according to the present embodiment. Asdescribed above, at the center of the screw-opposed surface 52, there isformed a communication hole 56 communicated with the ejection section60. On the periphery of the communication hole 56 in the screw-opposedsurface 52, there is formed a plurality of guide grooves 54. Each of theguide grooves 54 is coupled to the communication hole 56 at one end, andextends in a vortical manner from the communication hole 56 toward theouter circumference of the screw-opposed surface 52. Each of the guidegrooves 54 has a function of guiding the shaping material to thecommunication hole 56.

FIG. 4 is an explanatory diagram showing a configuration of the ejectionamount control mechanism 70 and a transfer mechanism 90 in the presentembodiment. FIG. 5 is a perspective view showing a configuration of thevalve part 73 of the ejection amount control mechanism 70 in the presentembodiment. The ejection section 60 is provided with the ejection amountcontrol mechanism 70 described above and the transfer mechanism 90. Thefirst supply port 65 and the second supply port 67 provided to theejection section 60 each extend in the vertical direction as describedabove. The through hole 66 extends in the horizontal direction. Thefirst supply port 65 and the second supply port 67 are coupled to thethrough hole 66 at respective positions shifted in the horizontaldirection from each other.

As described above, the ejection amount control mechanism 70 is providedwith the valve part 73 having a cylindrical shape and disposed insidethe through hole 66. The valve part 73 has a central axis AX1. In thevalve part 73, there is disposed a recessed part 75 by cutting a part ofan outer circumference of the cylindrical shape so as to have asemilunar shape. The recessed part 75 extends along the central axis AX1from below the first supply port 65 to above the second supply port 67.The valve part 73 is provided with a communication part 76 having agroove shape disposed on the outer circumference of the cylindricalshape along the central axis AX1 from a wall surface of the valve part73 defining the recessed part 75 to a tip part on the −Y direction sideof the valve part 73. The communication part 76 communicates the firstsupply port 65 and a second branch port 93 described later with eachother. In an end part in the +Y direction side of the valve part 73,there is disposed an operation part 77. To the operation part 77, thereis coupled a first drive section 81. By the torque due to the firstdrive section 81 being applied to the operation part 77, the valve part73 rotates. It should be noted that the communication part 76 can alsobe a hole instead of the groove, the hole penetrating from the wallsurface of the valve part 73 defining the recessed part 75 to the tippart on the −Y direction side of the valve part 73. The recessed part 75is also referred to as a flow passage in some cases.

FIG. 6 is a first explanatory diagram showing an operation of the valvepart 73. FIG. 7 is a second explanatory diagram showing the operation ofthe valve part 73. As shown in FIG. 6 , when the valve part 73 rotatesso that the recessed part 75 is located above, the second supply port 67is blocked by the valve part 73 to block off the inflow of the shapingmaterial from the first supply port 65 to the second supply port 67. Incontrast, when the valve part 73 rotates so that the recessed part 75faces to the +X direction or the −X direction as shown in FIG. 7 , thefirst supply port 65 and the second supply port 67 are communicated witheach other, and thus, the shaping material inflows from the first supplyport 65 to the second supply port 67 at the maximum flow rate. In otherwords, the cross-sectional area of the flow channel between the firstsupply port 65 and the second supply port 67 changes in accordance withthe rotation of the valve part 73, and thus, the flow rate of theshaping material inflowing from the first supply port 65 to the secondsupply port 67 changes.

The transfer mechanism 90 will be described with reference to FIG. 4 .The ejection section 60 is provided with a branch flow channel 91. Thebranch flow channel 91 has a first branch port 92 branched from thesecond supply port 67 and a second branch port 93 coupled to an end parton the −Y direction side of the through hole 66. The first branch port92 is coupled to an opening part disposed at one end of a cylinder 95.The second branch port 93 is coupled to an opening part disposed on aside surface of the cylinder 95. It should be noted that a part of thecylinder 95 located between the first branch port 92 and the secondbranch port 93 is also included in the branch flow channel 91.

The transfer mechanism 90 is provided with the cylinder 95 describedabove, a plunger 96 shaped like a shaft and disposed inside the cylinder95, a second drive section 82 for translating the plunger 96 inside thecylinder 95, and a check valve 94 disposed in the first branch port 92.The cylinder 95 has a central axis AX2. An end of the plunger 96 iscoupled to the second drive section 82 shown in FIG. 1 . The seconddrive section 82 is constituted by a stepping motor, a rack-and-pinionmechanism, a ball screw mechanism, or the like. The second drive section82 translates the plunger 96 along the central axis AX2 of the cylinder95 under the control by the control section 500. Translating the plunger96 so that the first branch port 92 gets away from an end part of thecylinder 95 on the side to which the first branch port 92 is coupled isreferred to as pulling the plunger 96. In contrast, translating theplunger 96 so that the first branch port 92 comes closer to the end partof the cylinder 95 on the side to which the first branch port 92 iscoupled is referred to as pushing the plunger 96. The check valve 94opens due to the pressure toward the cylinder 95 from the second supplyport 67, and closes due to the pressure toward the second supply port 67from the cylinder 95. Therefore, the check valve 94 allows the shapingmaterial to inflow from the second supply port 67 to the cylinder 95,and restricts outflow of the shaping material from the cylinder 95 tothe second supply port 67.

FIG. 8 is an explanatory diagram showing a flow of the shaping materialwhen pulling the plunger 96. In FIG. 8 , the direction of the flow ofthe shaping material is indicated using the arrow. The control section500 controls the second drive section 82 to pull the plunger 96. Whenthe plunger 96 has been pulled, since negative pressure occurs insidethe cylinder 95, the check valve 94 opens, and the shaping material inthe nozzle 61 and the second supply port 67 is suctioned into thecylinder 95 via the first branch port 92. It should be noted that due tothis operation, the shaping material which is in the process of beingejected from the nozzle 61 is pulled into the nozzle 61, and thus, it ispossible to achieve tail-cutting of the shaping material.

FIG. 9 is an explanatory diagram showing a flow of the shaping materialwhen pushing the plunger 96. In FIG. 9 , the direction of the flow ofthe shaping material is indicated using the arrow. The control section500 drives the second drive section 82 to push the plunger 96. When theplunger 96 has been pushed, since the inside of the cylinder 95 ispressurized, the check valve 94 is closed, and the shaping material inthe cylinder 95 is discharged to the inside of the recessed part 75 fromthe second branch port 93 through the communication part 76. Therefore,by pulling the plunger 96 to suction the shaping material into thecylinder 95 and then pushing the plunger 96, it is possible for thetransfer mechanism 90 to transfer the shaping material in the nozzle 61and the second supply port 67 to the inside of the recessed part 75.

FIG. 10 is a flowchart showing a content of a shaping process in thepresent embodiment. This process is executed by the control section 500when a predetermined start operation is performed by a user on anoperation panel provided to the three-dimensional shaping device 100 ora computer coupled to the three-dimensional shaping device 100.

Firstly, the control section 500 obtains shaping data of thethree-dimensional shaped article in the step S110. The shaping data isobtained from, for example, the computer or a recording medium coupledto the three-dimensional shaping device 100. The shaping data denotesdata for shaping the three-dimensional shaped article using thethree-dimensional shaping device 100. In the shaping data, there arerepresented a moving path of the nozzle 61 with respect to the stage300, an amount of ejection of the shaping material to be ejected fromthe nozzle 61 on the moving path, and so on. Shape data representing ashape of the three-dimensional shaped article generated usingthree-dimensional CAD software or three-dimensional CG software is readin, for example, slicer software on the computer coupled to thethree-dimensional shaping device 100, and thus, the shaping data isgenerated. As the shape data to be read in the slicer software, it ispossible to use data in the STL format, the AMF format, or the like.

Then, in the step S120, the control section 500 starts generation of theshaping material. The control section 500 controls the rotation of theflat screw 40, and the temperature of the heater 58 incorporated in thebarrel 50 to thereby melt the material to generate the shaping material.Due to the rotation of the flat screw 40, the material supplied from thematerial supply section 20 is introduced into the groove parts 45 fromthe material introduction ports 44 of the flat screw 40. The materialintroduced into the groove parts 45 is conveyed to the central part 47along the groove parts 45. The material conveyed inside the groove parts45 is at least partially melted due to the shear caused by a relativerotation between the flat screw 40 and the barrel 50 and heating by theheater 58, and thus, turns to the shaping material in paste form havingfluidity. The shaping material collected in the central part 47 issupplied to the ejection section 60 through the communication hole 56due to the internal pressure generated in the central part 47. It shouldbe noted that the shaping material continues to be generated during theexecution of this process.

In the step S130, the control section 500 controls the ejection amountcontrol mechanism 70 to thereby communicate the first supply port 65 andthe second supply port 67 with each other to start ejection of theshaping material from the nozzle 61. By starting the ejection of theshaping material from the nozzle 61, shaping of the three-dimensionalshaped article is started.

In the step S140, the control section 500 determines whether or not theejection of the shaping material from the nozzle 61 is to be stopped.When it has not been determined in the step S140 that the ejection ofthe shaping material from the nozzle 61 is to be stopped, the controlsection 500 continues the shaping of the three-dimensional shapedarticle while repeating the process in the step S140 until it isdetermined in the step S140 that the ejection of the shaping materialfrom the nozzle 61 is to be stopped. In contrast, when it has beendetermined in the step S140 that the ejection of the shaping materialfrom the nozzle 61 is to be stopped, the control section 500 controlsthe ejection amount control mechanism 70 to thereby block off the inflowof the shaping material from the first supply port 65 to the secondsupply port 67 in the step S150. By the inflow of the shaping materialfrom the first supply port 65 to the second supply port 67 being blockedoff, the ejection of the shaping material from the nozzle 61 is stopped.

After the inflow of the shaping material from the first supply port 65to the second supply port 67 is blocked off, the control section 500controls the second drive section 82 to pull the plunger 96 in the stepS160 to suction the shaping material remaining in the nozzle 61 and thesecond supply port 67 into the cylinder 95. In the step S170, thecontrol section 500 controls the second drive section 82 to push theplunger 96 to thereby discharge the shaping material having beensuctioned into the cylinder 95 to the inside of the recessed part 75.

Subsequently, in the step S180, the control section 500 determineswhether or not the shaping of the three-dimensional shaped article hasbeen completed. When it has not been determined in the step S180 thatthe shaping of the three-dimensional shaped article has been completed,the control section 500 determines in the step S190 whether or not theejection of the shaping material from the nozzle 61 is to be resumed.When it has been determined in the step S190 that the ejection of theshaping material from the nozzle 61 is to be resumed, the controlsection 500 returns the process to the step S130 to control the ejectionamount control mechanism 70 to thereby communicate the first supply port65 and the second supply port 67 with each other to resume the ejectionof the shaping material from the nozzle 61. By the ejection of theshaping material from the nozzle 61 being resumed, shaping of thethree-dimensional shaped article is resumed. In contrast, when it hasnot been determined in the step S190 that the ejection of the shapingmaterial from the nozzle 61 is to be resumed, the control section 500stands ready to shape the three-dimensional shaped article whilerepeating the process in the step S190 until it is determined that theejection of the shaping material from the nozzle 61 is to be resumed.

When it has been determined in the step S180 that the shaping of thethree-dimensional shaped article has been completed, the control section500 terminates this process. In such a manner, the three-dimensionalshaped article is shaped on the stage 300.

According to the three-dimensional shaping device 100 according to thepresent embodiment described hereinabove, the control section 500controls the ejection amount control mechanism 70 to transfer theshaping material in the nozzle 61 and the second supply port 67 to theinside of the recessed part 75 in a period from stopping the ejection ofthe shaping material from the nozzle 61 to resuming the ejection.Therefore, it is possible to prevent the shaping material from droopinglike a filament from the nozzle to cause so called stringing, and theshaping material remaining in the nozzle 61 and the second supply port67 from denaturing. In particular, in the present embodiment, thecontrol section 500 controls the second drive section 82 to pull theplunger 96 to thereby suction the shaping material in the nozzle 61 andthe second supply port 67 into the cylinder 95, and to push the plunger96 while preventing the outflow of the shaping material from the insideof the cylinder 95 to the inside of the second supply port 67 by thecheck valve 94 to thereby discharge the shaping material thus suctionedinto the cylinder 95 to the inside of the recessed part 75. Therefore,it is possible to effectively transfer the shaping material in thenozzle 61 and the second supply port 67 into the recessed part 75 due tothe reciprocation of the plunger 96.

Further, in the present embodiment, since the control section 500controls the first drive section 81 to rotate the valve part 73 tothereby communicate the first supply port 65 and the second supply port67 with each other, it is possible to start and stop the ejection of theshaping material from the nozzle 61. Therefore, it is possible to startand stop the ejection of the shaping material from the nozzle 61 with asimple configuration.

Further, in the present embodiment, it is possible to heat the shapingmaterial in the nozzle 61 and the second supply port 67 using the nozzleheater 160. Therefore, it is possible to enhance the fluidity of theshaping material to be ejected from the nozzle 61. In particular, in thepresent embodiment, it is possible to transfer the shaping material inthe nozzle 61 and the second supply port 67 located close to the nozzleheater 160 to the inside of the recessed part 75 distant from the nozzleheater 160. Therefore, it is possible to prevent the shaping material inthe nozzle 61 and the second supply port 67 from receiving the heat fromthe nozzle heater 160 for a long period of time to thereby denatureduring a period in which the ejection of the shaping material from thenozzle 61 is stopped.

It should be noted that although in the present embodiment, the ABSresin shaped like a pellet is used as the material, a material forshaping the three-dimensional shaped article including a variety ofmaterials such as a material having thermoplastic property, a metalmaterial, or a ceramic material as a principal material can also beadopted as the material used in the shaping unit 200. Here, the“principal material” means the material playing a central role forforming the shape of the three-dimensional shaped article, and means thematerial having a content rate not lower than 50% by weight in thethree-dimensional shaped article. The shaping material described aboveincludes those obtained by melting the principal material thereof alone,or those obtained by melting some of the components included thereintogether with the principal material in paste form.

The material having a thermoplastic property as the principal materialis used, the material plasticizes in the melting section 30 to therebygenerate the shaping material. The term “plasticization” means that heatis applied to the material having the thermoplastic property to melt thematerial. Further, the term “melt” also means that the material having athermoplastic property is heated at a temperature not lower than theglass-transition point to thereby be softened, and thus, the fluidity isdeveloped.

As the material having a thermoplastic property, for example, it ispossible to use any one of the following thermoplastic resin materialsor a thermoplastic resin material obtained by combining two or more ofthe following thermoplastic resin materials.

Examples of Thermoplastic Resin Material

general-purpose engineering plastic such as polypropylene resin (PP),polyethylene resin (PE), polyacetal resin (POM), polyvinyl chlorideresin (PVC), polyamide resin (PA), acrylonitrile-butadiene-styrene resin(ABS), polylactic resin (PLA), polyphenylene sulfide resin (PPS),polycarbonate (PC), modified polyphenylene ether, polybutyleneterephthalate, or polyethylene terephthalate, engineering plastic suchas polysulfone, polyether sulfone, polyphenylene sulfide, polyarylate,polyimide, polyamide-imide, polyetherimide, or polyether ether ketone(PEEK)

In the material having a thermoplastic property, there can be mixedpigment, metal, ceramic, and in addition, an additive agent such as wax,flame retardant, antioxidant, or thermal stabilizer, and so on. In themelting section 30, the material having a thermoplastic property isplasticized by the rotation of the flat screw 40 and heating by theheater 58 to be transformed into the melted state. Further, the shapingmaterial generated in such a manner is ejected from the nozzle 69, andthen cures due to drop in temperature.

It is desirable for the material having a thermoplastic property to beheated at a temperature not lower than the glass-transition point andthen ejected from the nozzle hole 69 in the completely melted state. Itshould be noted that the “completely melted state” means the state inwhich there is no unmelted material having a thermoplastic property, andmeans the state in which no solid matter shaped like a pellet remainswhen, for example, using the thermoplastic resin shaped like a pellet asthe material.

In the shaping unit 200, the following metal material, for example, canbe used as the principal material instead of the material having athermoplastic property described above. In this case, it is desirablethat the components to be melted when generating the shaping materialare mixed in a powder material obtained by powdering the metal materialdescribed below, and then the mixture is loaded into the melting section30.

Example of Metal Material

magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al),titanium (Ti), copper (Co), or nickel (Ni) as a single metal, or alloysincluding one or more of these metals

Example of Alloy

maraging steel, stainless steel, cobalt-chromium-molybdenum, titaniumalloy, nickel alloy, aluminum alloy, cobalt alloy, and cobalt-chromealloy)

In the shaping unit 200, it is possible to use a ceramic material as theprincipal material instead of the metal material described above. As theceramic material, it is possible to use, for example, oxide ceramicssuch as silicon dioxide, titanium dioxide, aluminum oxide, or zirconiumoxide, and non-oxide ceramics such as aluminum nitride. When using themetal material or the ceramic material described above as the principalmaterial, it is possible for the shaping material disposed on the stage300 to be made to cure by calcination due to, for example, irradiationwith a laser or hot air.

The powder material of the metal material or the ceramic material to beloaded into the material supply section 20 can also be a mixed materialobtained by mixing a plurality of types of single metal powder, alloypowder, or ceramic material powder. Further, the powder material of themetal material or the ceramic material can also be coated with, forexample, the thermoplastic resin as illustrated above or otherthermoplastic resin. In this case, it is also possible to assume thatthe thermoplastic resin is melted to develop the fluidity in the meltingsection 30.

It is also possible to add, for example, the following solvent to thepowder material of the metal material or the ceramic material to beloaded into the material supply section 20. As the solvent, it is alsopossible to use one species selected from the following, or two or morespecies selected from the following in combination.

Example of Solvent

water; a (poly)alkylene glycol monoalkyl ether group such as ethyleneglycol monomethyl ether, ethylene glycol monoethyl ether, propyleneglycol monomethyl ether, or propylene glycol monoethyl ether; an esteracetate group such as ethyl acetate, n-propyl acetate, isopropylacetate, n-butyl acetate, or isobutyl acetate; an aromatic hydrocarbongroup such as benzene, toluene, or xylene; a ketone group such as methylethyl ketone, acetone, methyl isobutyl ketone, ethyl-n-butyl ketone,diisopropyl ketone, or acetylacetone; an alcohol group such as ethanol,propanol, or butanol; a tetraalkylammonium acetate group; a sulfoxideseries solvent such as dimethyl sulfoxide, or diethyl sulfoxide; apyridine series solvent such as pyridine, γ-picoline, or 2,6-lutidine;tetraalkylammonium acetate (e.g., tetrabutylammonium acetate); an ionicliquid such as butyl carbitol acetate

Besides the above, it is also possible to add, for example, thefollowing binder to the powder material of the metal material or theceramic material to be loaded into the material supply section 20.

Example of Binder

acrylic resin, epoxy resin, silicone resin, cellulosic resin, or othersynthetic resin, polylactic acid (PLA), polyamide (PA), polyphenylenesulfide (PPS), polyether ether ketone (PEEK), or other thermoplasticresin

B. Second Embodiment

FIG. 11 is a flowchart showing a content of the shaping process executedin a three-dimensional shaping device 100 b according to a secondembodiment. The second embodiment is different in the content of theshaping process from the first embodiment. The other configurations arethe same as those of the first embodiment shown in FIG. 1 unlessparticularly described.

The content of the process in the steps S210 through S260 is the same asin the first embodiment. The control section 500 controls the seconddrive section 82 to pull the plunger 96 in the step S260, and thendetermines in the step S280 whether or not shaping of thethree-dimensional shaped article has been completed. When it has beendetermined in the step S280 that the shaping of the three-dimensionalshaped article has been completed, the control section 500 terminatesthis process. In contrast, when it has not been determined in the stepS280 that the shaping of the three-dimensional shaped article has beencompleted, the control section 500 determines in the step S290 whetheror not the ejection of the shaping material from the nozzle 61 is to beresumed.

When it has not been determined in the step S290 that the ejection ofthe shaping material from the nozzle 61 is to be resumed, the controlsection 500 stands ready to shape the three-dimensional shaped articlewhile repeating the process in the step S290 until it is determined thatthe ejection of the shaping material from the nozzle 61 is to beresumed. In contrast, when it has been determined in the step S290 thatthe ejection of the shaping material from the nozzle 61 is to beresumed, the control section 500 controls the ejection amount controlmechanism 70 in the step S295 to thereby communicate the first supplyport 65 and the second supply port 67 with each other, and then controlsthe second drive section 82 in the step S296 to push the plunger 96. Bypushing the plunger 96 after the first supply port 65 and the secondsupply port 67 are communicated with each other, the shaping material inthe cylinder 95 is discharged to the inside of the recessed part 75.Therefore, the shaping material inflowing into the second supply port 67is pressurized, and thus, the ejection of the shaping material from thenozzle 61 is promptly resumed. Therefore, the shaping of thethree-dimensional shaped article is promptly resumed.

According to the three-dimensional shaping device 100 b in the presentembodiment described hereinabove, the control section 500 controls theejection amount control mechanism 70 to block off the inflow of theshaping material from the first supply port 65 into the second supplyport 67, and then controls the second drive section 82 to pull theplunger 96 to thereby suction the shaping material in the nozzle and thesecond supply port 67 into the cylinder 95. Subsequently, the controlsection 500 controls the ejection amount control mechanism 70 tocommunicate the first supply port 65 and the second supply port 67 witheach other, and then controls the second drive section 82 to push theplunger 96 to thereby discharge the shaping material thus suctioned intothe cylinder 95 to the inside of the recessed part 75. In other words,the control section 500 resumes the supply of the shaping material fromthe first supply port 65 to the second supply port 67, and thenterminates the transfer of the shaping material by the transfermechanism 90. By discharging the shaping material located in thecylinder 95 to the inside of the recessed part 75 after the first supplyport 65 and the second supply port 67 are communicated with each other,it is possible to pressurize the shaping material inflowing into thesecond supply port 67. Therefore, the ejection of the shaping materialfrom the nozzle 61 is promptly resumed. Therefore, it is possible toimprove the response in ejecting the shaping material from the nozzle 61when resuming the ejection of the shaping material from the nozzle 61.

C. Third Embodiment

FIG. 12 is a flowchart showing a content of the shaping process executedin a three-dimensional shaping device 100 c according to a thirdembodiment. The third embodiment is different in the content of theshaping process from the first embodiment. The other configurations arethe same as those of the first embodiment shown in FIG. 1 unlessparticularly described.

The content of the process in the steps S310 through S360 is the same asin the first embodiment. The control section 500 controls the ejectionamount control mechanism 70 in the step S350 to stop the ejection of theshaping material from the nozzle 61, then controls the second drivesection 82 in the step S360 to pull the plunger 96, and then determinesin the step S380 whether or not the shaping of the three-dimensionalshaped article has been completed. When it has been determined in thestep S380 that the shaping of the three-dimensional shaped article hasbeen completed, the control section 500 terminates this process. Incontrast, when it has not been determined in the step S380 that theshaping of the three-dimensional shaped article has been completed, thecontrol section 500 executes the transfer process in the step S400.

FIG. 13 is a flowchart showing a content of the transfer process in thepresent embodiment. In the step S410, the control section 500 determineswhether or not a predetermined time has elapsed after controlling theejection amount control mechanism 70 to stop the ejection of the shapingmaterial from the nozzle 61. The predetermined time can be set as thetime within a range in which the shaping material does not denature inthe nozzle 61 or the second supply port 67 by examining the time fromcontrolling the ejection amount control mechanism 70 to stop theejection of the shaping material from the nozzle 61 to when the shapingmaterial in the nozzle 61 and the second supply port 67 denatures withthe experiment performed in advance.

When it has not been determined in the step S410 that the predeterminedtime has elapsed after controlling the ejection amount control mechanism70 to stop the ejection of the shaping material from the nozzle 61, thecontrol section 500 determines in the step S420 whether to resume theejection of the shaping material from the nozzle 61. When it has notbeen determined in the step S420 that the ejection of the shapingmaterial from the nozzle 61 is to be resumed, the control section 500returns the process to the step S410 to determine whether or not thepredetermined time has elapsed after controlling the ejection amountcontrol mechanism 70 to stop the ejection of the shaping material fromthe nozzle 61 once again. In contrast, when it has been determined inthe step S420 that the ejection of the shaping material from the nozzle61 is to be resumed, namely when it has been determined that theejection of the shaping material from the nozzle 61 is to be resumedbefore the predetermined time elapses after controlling the ejectionamount control mechanism 70 to stop the ejection of the shaping materialfrom the nozzle 61, the control section 500 controls the ejection amountcontrol mechanism 70 in the step S430 to communicate the first supplyport 65 and the second supply port 67 with each other, and then controlsthe second drive section 82 in the step S440 to push the plunger 96. Bypushing the plunger 96 after the first supply port 65 and the secondsupply port 67 are communicated with each other, the shaping materialinflowing into the second supply port 67 is pressurized, and thus, theejection of the shaping material from the nozzle 61 is promptly resumed.Therefore, the shaping of the three-dimensional shaped article ispromptly resumed.

When it has been determined in the step S410 that the predetermined timehas elapsed after controlling the ejection amount control mechanism 70to stop the ejection of the shaping material from the nozzle 61, namelywhen it has not been determined that the ejection of the shapingmaterial from the nozzle 61 is to be resumed until the predeterminedtime has elapsed after controlling the ejection amount control mechanism70 to stop the ejection of the shaping material from the nozzle 61, thecontrol section 500 controls the second drive section 82 in the stepS450 to thereby push the plunger 96. By pushing the plunger 96, theshaping material located in the cylinder 95 is discharged to the insideof the recessed part 75. Subsequently, in the step S460, the controlsection 500 determines whether or not the ejection of the shapingmaterial from the nozzle 61 is to be resumed. When it has not beendetermined in the step S460 that the ejection of the shaping materialfrom the nozzle 61 is to be resumed, the control section 500 standsready to shape the three-dimensional shaped article while repeating theprocess in the step S460 until it is determined that the ejection of theshaping material from the nozzle 61 is to be resumed. In contrast, whenit has been determined in the step S460 that the ejection of the shapingmaterial from the nozzle 61 is to be resumed, the control section 500controls the ejection amount control mechanism 70 in the step S470 tothereby communicate the first supply port 65 and the second supply port67 with each other to resume the ejection of the shaping material fromthe nozzle 61. By the ejection of the shaping material from the nozzle61 being resumed, shaping of the three-dimensional shaped article isresumed.

According to the three-dimensional shaping device 100 c in the presentembodiment described hereinabove, when it has not been determined thatthe ejection of the shaping material from the nozzle 61 is to be resumeduntil the predetermined time has elapsed after controlling the ejectionamount control mechanism 70 to stop the ejection of the shaping materialfrom the nozzle 61, the control section 500 pushes the plunger 96 todischarge the shaping material from the inside of the cylinder 95 to theinside of the recessed part 75. Therefore, it is possible to prevent theshaping material in the cylinder 95 from denaturing. In contrast, whenit has been determined that the ejection of the shaping material fromthe nozzle 61 is to be resumed before the predetermined time elapsesafter controlling the ejection amount control mechanism 70 to stop theejection of the shaping material from the nozzle 61, the control section500 controls the ejection amount control mechanism 70 to communicate thefirst supply port 65 and the second supply port 67 with each other, andthen pushes the plunger 96 to discharge the shaping material from theinside of the cylinder 95 to the inside of the recessed part 75. Bydischarging the shaping material located in the cylinder 95 to theinside of the recessed part 75 after the first supply port 65 and thesecond supply port 67 are communicated with each other, it is possibleto pressurize the shaping material inflowing into the second supply port67. Therefore, the ejection of the shaping material from the nozzle 61is promptly resumed. Therefore, it is possible to improve the responsein ejecting the shaping material from the nozzle 61 when resuming theejection of the shaping material from the nozzle 61. Therefore, it ispossible to prevent the shaping material from denaturing in the cylinder95 while improving the response in ejecting the shaping material fromthe nozzle 61.

D. Other Embodiments

-   -   (D1) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the transfer mechanism 90 is constituted by the cylinder 95, the        plunger 96, and the check valve 94. In contrast, it is also        possible for the transfer mechanism 90 to be formed of a pump        coupled to the first branch port 92 and the second branch port        93.    -   (D2) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the transfer mechanism 90 is provided with the check valve 94        disposed in the first branch port 92. In contrast, the transfer        mechanism 90 is not required to be provided with the check valve        94. In this case, for example, it is possible to adopt a        configuration in which the shaping material in the cylinder 95        is discharged to the second branch port 93 when pushing the        plunger 96 by setting the pressure loss in the first branch port        92 larger than the pressure loss in the second branch port 93        and the communication part 76.    -   (D3) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the check valve 94 is disposed in the first branch port 92. In        contrast, it is also possible to adopt a configuration in which        the check valve 94 is not disposed in the first branch port 92,        but a check valve for restricting the inflow of the shaping        material from the first supply port 65 to the cylinder 95 is        disposed in the second branch port 93. In this case, for        example, it is possible to adopt a configuration in which the        shaping material in the cylinder 95 is discharged to the second        branch port 93 when pushing the plunger 96 by setting the        pressure loss in the first branch port 92 larger than the        pressure loss in the second branch port 93 and the communication        part 76. Further, by disposing the check valve in the second        branch port 93, it is possible to prevent the shaping material        in the first support port 65 from flowing into the cylinder 95        from the second branch port 93.    -   (D4) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the check valve 94 is disposed in the first branch port 92. In        contrast, it is also possible to adopt a configuration in which        the check valve 94 is disposed in the first branch port 92, and        further, a check valve for restricting the inflow of the shaping        material from the first supply port 65 to the cylinder 95 is        disposed in the second branch port 93. In this case, it is        possible to prevent the inflow of the shaping material from the        first supply port 65 to the cylinder 95, and at the same time,        it is possible to prevent the outflow of the shaping material        from the cylinder 95 to the second supply port 67.    -   (D5) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the first branch port 92 and the second branch port 93 are        coupled to each other via the cylinder 95. In contrast, the        first branch port 92 and the second branch port 93 can also be        directly coupled to each other. Also in this case, by coupling        the cylinder 95 to the coupling part between the first branch        port 92 and the second branch port 93, it is possible to suction        the shaping material in the nozzle 61 and the second supply port        67 into the cylinder 95 via the first branch port 92, and to        discharge the shaping material in the cylinder 95 to the inside        of the recessed part 75 via the second branch port 93.    -   (D6) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the first branch port 92 is coupled to the second supply port        67. In contrast, the first branch port 92 can also be coupled to        the nozzle flow channel 68.    -   (D7) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the second branch port 93 is coupled to the first supply port        65. In contrast, the second branch port 93 can also be coupled        to the communication hole 56 of the barrel 50. In this case, it        is not required to provide the communication part 76 to the        valve part 73 of the ejection amount control mechanism 70.    -   (D8) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the ejection amount control mechanism 70 can be formed of a gate        valve, a globe valve, a ball valve, or the like.    -   (D9) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the nozzle heater 160 can be eliminated.    -   (D10) In the three-dimensional shaping devices 100, 100 b, and        100 c according to the respective embodiments described above,        the melting section 30 is provided with the flat screw 40, and        melts the material using the rotation of the flat screw 40. In        contrast, it is also possible for the melting section 30 to be        provided with an in-line screw having a spiral groove formed on        the elongated shaft instead of the flat screw 40, and to melt        the material using the rotation of the in-line screw.

E. Other Aspects

The present disclosure is not limited to the embodiments describedabove, but can be implemented in a variety of aspects within the scopeor the spirit of the disclosure. For example, the present disclosure canalso be implemented in the following aspects. The technical features ineach of the embodiments described above corresponding to the technicalfeatures in each of the aspects described below can arbitrarily bereplaced or combined in order to solve a part or the whole of theproblem of the present disclosure, or to achieve some or all of theadvantages of the present disclosure. Further, the technical feature canarbitrarily be eliminated unless described in the present specificationas an essential element.

-   -   (1) According to a first aspect of the present disclosure, there        is provided a three-dimensional shaping device. The        three-dimensional shaping device includes a melting section        configured to melt a material to generate a shaping material, a        supply flow channel which is communicated with the melting        section, and through which the shaping material flows, a nozzle        communicated with the supply flow channel and configured to        eject the shaping material, an ejection amount control mechanism        provided to the supply flow channel, and configured to control a        flow amount of the shaping material to be ejected from the        nozzle, a branch flow channel branched from a first partial flow        channel as a flow channel between the melting section and the        ejection amount control mechanism out of the supply flow        channel, and communicated with a second partial flow channel as        a flow channel between the ejection amount control mechanism and        the nozzle out of the supply flow channel, a transfer mechanism        configured to transfer the shaping material in the second        partial flow channel to the first partial flow channel via the        branch flow channel, and a control section configured to control        the ejection amount control mechanism and the transfer        mechanism. The control section controls the transfer mechanism        to transfer the shaping material in the second partial flow        channel to the first partial flow channel in a period obtained        by summing a first period from controlling the ejection amount        control mechanism to stop ejection of the shaping material from        the nozzle to controlling the ejection amount control mechanism        to resume the ejection of the shaping material from the nozzle,        and a second period after controlling the ejection amount        control mechanism to resume the ejection of the shaping material        from the nozzle.

According to the three-dimensional shaping device, since the controlsection transfers the shaping material in the nozzle and the secondpartial flow channel to the first partial flow channel via the branchflow channel after stopping the supply of the shaping material from thefirst partial flow channel to the nozzle, it is possible to preventstringing of the shaping material from the nozzle and denaturation ofthe shaping material in the nozzle and the second partial flow channel.

-   -   (2) In the three-dimensional shaping device according to the        aspect described above, the control section may control the        transfer mechanism to transfer the shaping material in the        second partial flow channel to the first partial flow channel in        the first period.

According to the three-dimensional shaping device of this aspect, thestringing of the shaping material from the nozzle and the denaturationof the shaping material in the nozzle and the second partial flowchannel can more surely be prevented.

-   -   (3) In the three-dimensional shaping device according to the        aspect described above, the control section may control the        transfer mechanism to make the shaping material in the second        partial flow channel flow out to the branch flow channel in the        first period, and the control section may control the transfer        mechanism to make the shaping material in the branch flow        channel inflow to the first partial flow channel in the second        period.

According to the three-dimensional shaping device of this aspect, sinceit is possible to pressurize the shaping material inflowing to thesecond partial flow channel when resuming the supply of the shapingmaterial from the first partial flow channel to the second partial flowchannel, it is possible to improve the response in ejecting the shapingmaterial from the nozzle.

-   -   (4) In the three-dimensional shaping device according to the        aspect described above, the control section may control the        transfer mechanism to make the shaping material in the second        partial flow channel flow out to the branch flow channel in the        first period, the control section may control the transfer        mechanism to make the shaping material in the branch flow        channel inflow to the first partial flow channel in the first        period when the first period is not shorter than a predetermined        period, and the control section may control the transfer        mechanism to make the shaping material in the branch flow        channel inflow to the first partial flow channel in the second        period when the first period is shorter than the predetermined        period.

According to the three-dimensional shaping device of this aspect, it ispossible to prevent the denaturation of the shaping material in thenozzle and the second partial flow channel while improving the responsein ejecting the shaping material from the nozzle.

-   -   (5) In the three-dimensional shaping device according to the        aspect described above, the transfer mechanism may include a        cylinder having a cylindrical shape and communicated with the        branch flow channel, a plunger reciprocating in the cylinder,        and a check valve which is disposed in a part between the second        partial flow channel and the cylinder out of the branch flow        channel, and is configured to prevent outflow of the shaping        material from the cylinder to the second partial flow channel.

According to the three-dimensional shaping device of this aspect, it ispossible to effectively transfer the shaping material in the secondpartial flow channel to the first partial flow channel due to thereciprocation of the plunger while preventing the outflow of the shapingmaterial from the cylinder to the second partial flow channel with thecheck valve.

-   -   (6) In the three-dimensional shaping device according to the        aspect described above, the ejection amount control mechanism        may include a valve part which is configured to be able to        rotate in the supply flow channel, and has a flow passage        through which the shaping material flows, and the ejection        amount control mechanism may change a flow amount of the shaping        material flowing from the first partial flow channel into the        second partial flow channel via the flow passage in accordance        with a rotation of the valve part.

According to the three-dimensional shaping device of this aspect, it ispossible to control the flow amount of the shaping material to beejected from the nozzle with a simple configuration.

-   -   (7) The three-dimensional shaping device according to the aspect        described above may further include a heating section configured        to heat the shaping material in the second partial flow channel.

According to the three-dimensional shaping device of this aspect, it ispossible to enhance the fluidity of the shaping material to be ejectedfrom the nozzle by heating the shaping material in the second partialflow channel using the heating section.

The present disclosure can be implemented in a variety of aspects otherthan the three-dimensional shaping device. For example, the presentdisclosure can also be implemented as an aspect such as a method ofcontrolling a three-dimensional shaping device or a method of shaping athree-dimensional shaped article.

What is claimed is:
 1. A three-dimensional shaping device comprising: amelting section configured to melt a material to generate a shapingmaterial; a supply flow channel which is communicated with the meltingsection, and through which the shaping material flows; a nozzlecommunicated with the supply flow channel and configured to eject theshaping material; an ejection amount control mechanism provided to thesupply flow channel, and configured to control a flow amount of theshaping material to be ejected from the nozzle; a branch flow channelbranched from a first partial flow channel as a flow channel between themelting section and the ejection amount control mechanism out of thesupply flow channel, and communicated with a second partial flow channelas a flow channel between the ejection amount control mechanism and thenozzle out of the supply flow channel; a transfer mechanism configuredto transfer the shaping material in the second partial flow channel tothe first partial flow channel via the branch flow channel; and acontrol section configured to control the ejection amount controlmechanism and the transfer mechanism, wherein the control section isconfigured to control the transfer mechanism to transfer the shapingmaterial in the second partial flow channel to the first partial flowchannel in a period obtained by summing a first period from controllingthe ejection amount control mechanism to stop ejection of the shapingmaterial from the nozzle to controlling the ejection amount controlmechanism to resume the ejection of the shaping material from thenozzle, and a second period after controlling the ejection amountcontrol mechanism to resume the ejection of the shaping material fromthe nozzle and before controlling the ejection amount control mechanismto stop ejection of the shaping material from the nozzle a second time.2. The three-dimensional shaping device according to claim 1, whereinthe control section is configured to control the transfer mechanism totransfer the shaping material in the second partial flow channel to thefirst partial flow channel in the first period.
 3. The three-dimensionalshaping device according to claim 1, wherein the control section isconfigured to control the transfer mechanism to make the shapingmaterial in the second partial flow channel flow out to the branch flowchannel in the first period, and the control section is configured tocontrol the transfer mechanism to make the shaping material in thebranch flow channel inflow to the first partial flow channel in thesecond period.
 4. The three-dimensional shaping device according toclaim 1, wherein the control section is configured to control thetransfer mechanism to make the shaping material in the second partialflow channel flow out to the branch flow channel in the first period,the control section is configured to control the transfer mechanism tomake the shaping material in the branch flow channel inflow to the firstpartial flow channel in the first period when the first period is notshorter than a predetermined period, and the control section isconfigured to control the transfer mechanism to make the shapingmaterial in the branch flow channel inflow to the first partial flowchannel in the second period when the first period is shorter than thepredetermined period.
 5. The three-dimensional shaping device accordingto claim 1, wherein the transfer mechanism includes a cylinder having acylindrical shape and communicated with the branch flow channel, aplunger reciprocating in the cylinder, and a check valve which isdisposed in a part between the second partial flow channel and thecylinder out of the branch flow channel, and is configured to preventoutflow of the shaping material from the cylinder to the second partialflow channel.
 6. The three-dimensional shaping device according to claim1, wherein the ejection amount control mechanism includes a valve partwhich is configured to be able to rotate in the supply flow channel, andhas a flow passage through which the shaping material flows, and theejection amount control mechanism changes a flow amount of the shapingmaterial flowing from the first partial flow channel into the secondpartial flow channel via the flow passage in accordance with a rotationof the valve part.
 7. The three-dimensional shaping device according toclaim 1, further comprising: a heating section configured to heat theshaping material in the second partial flow channel.